The present invention relates to wrenches and, more particularly, to a reversible ratchet wrench, which has a simple structure, and is easy to operate.
Various reversible ratchet wrenches have been disclosed, and have appeared on the market. Conventional reversible ratchet wrenches are commonly complicated, and therefore their manufacturing cost is high. FIG. 8 shows a reversible ratchet wrench according to the prior art. This structure of reversible ratchet wrench comprises a casing, a ratchet wheel, two movable stop members, a spring, and a control wheel. The casing is a hollow cylindrical member, comprising a receiving chamber, which holds the ratchet wheel, enabling the ratchet wheel to be rotated with the tool bit holder shank attached thereto, and a side opening, which receives the stop members at two sides of the ratchet wheel. The spring forces the stop members into engagement with the ratchet wheel to stop the ratchet wheel from rotary motion relative to the casing. The control wheel is revolvably mounted on the casing, having a protruded block. By means of rotating the control wheel leftwards or rightwards, the protruded block is alternatively pressed on the stop members to control the direction of rotation of the ratchet wheel relative to the casing. Because this structure of reversible ratchet wheel is complicated, its manufacturing cost is high.
The present invention has been accomplished under the circumstances in view. It is the main object of the present invention to provide a simple structure of reversible ratchet wheel, which is inexpensive to manufacture. It is another object of the present invention to provide a simple structure ot reversible ratchet wheel, which is easy to operate. The reversible ratchet wheel of the present invention comprises a casing fastened to a tool handle to hold a tool bit holder shank and a tool bit at the shank, a forward control ratchet wheel and a backward control ratchet wheel concentrically mounted in the casing, first and second springs respectively mounted in the casing to support the forward control ratchet wheel and the backward control ratchet wheel respectively, a stop control ratchet wheel coupled to the tool bit holder shank tor synchronous motion, a third spring adapted to force the stop control ratchet wheel into engagement with the forward control ratchet wheel and the backward control ratchet wheel, and a rotary control knob mounted on the casing and turned between a first position where the stop control ratchet wheel is maintained meshed with the forward control ratchet wheel and the backward control ratchet wheel, a second position where the forward control ratchet wheel is disengaged from the stop control ratchet wheel tor enabling the tool bit holder shank to be rotated with the stop control ratchet wheel in one direction, and a third position where the backward control ratchet is disengaged from the stop control ratchet wheel for enabling the tool bit holder shank to be rotated with the stop control ratchet wheel in the reversed direction.